/Engine/Plugins/Experimental/GeometryScripting/Source/GeometryScriptingEditor/Public/GeometryActors/GeneratedDynamicMeshActor.h
Mark this Actor as modified so that OnRebuildGeneratedMesh runs
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="DynamicMeshActor") void MarkForMeshRebuild ( bool bImmediate, bool bImmediateEvenIfFrozen )